1. Technical Field
The present invention is directed toward mechanical window operators, and more particularly toward operators for controlling movement and locking of casement or awning type windows.
2. Background Art
Casement and awning type windows are well known in the art in which a window sash pivots about one of its sides for opening and closing relative to a window frame on which it is supported. Many different types of window (and other closure) operators which are well known in the art for accomplishing this operation.
Of course, it is also usually desirable to also provide a positive mechanical locking connection between the sash and the frame to provide security against the sash being forced open by an intruder trying to gain entry. Unfortunately, with many window operators, the lock structure is completely separate from the operator, with the result sometimes being that the person manipulating the operator to close the window inadvertently fails to also positively lock the window.
Accordingly, some operators have been constructed so that manipulation of the operator structure will automatically sequentially operate the locking structure as well.
Examples of such operators are shown, for example, in Tucker et al. U.S. Pat. No. 5,152,103, Tucker et al U.S. Pat. No. 4,937,976, Vetter U.S. Pat. No. 4,497,135, Payne U.S. Pat. No. 2,538,980, and Flagg U.S. Pat. No. 1,724,011.
For example, Flagg U.S. Pat. No. 1,724,011 uses a rack with a slot and pin arrangement to selectively operate either the window sash or the locking structure. Tucker et al. U.S. Pat. No. 4,937,976 discloses an operator structure in which a handle is rotated to control movement of a sash, with the handle also being pivotable between active and inactive positions where such separate pivoting operates a locking mechanism for the window.
Vetter U.S. Pat. No. 4,497,135 discloses an automatic operator and locking mechanism in which separate gear drives on a corner of the sash are provided connecting an electric drive motor to the sash operator and lock mechanism, respectively, with a sash operated trigger restraining the lock mechanism against operation when the sash is open.
Tucker et al, U.S. Pat. No. 5,152,103 is a combination operator and lock which has been found to meet the desirable characteristics of such structures. That is, it is simple to use not only when opening and closing the window, but also reliably ensures that the window automatically and properly unlocks and locks as it is opened and closed. Further, the Tucker et al. '103 structure is readily usable in any number of different configurations to provide whatever type of window operation is desirable.
One problem which has been found with the Tucker et al. '103 structure is that, during the short transition period during closing when the drive is disconnecting from the operator portion and connecting to the locking portion, the operation of the structure becomes indeterminate. That is, two different motions (of both the locking structure and the operating structure) are possible though only motion of the locking structure is desired. As a result, it is at least possible during such transition period that the sash would open whereby it would not be properly positioned for engagement by the locking structure as the locking motion proceeds. If that occurs (and it is a distinct possibility in cases where there is a pressure drop from the interior of the dwelling to the exterior, such pressure drop tending to constantly bias the sash toward opening), the structure must be manually reset. Further, if this failure to properly lock were not noticed by the dwelling occupant, it could present a dangerous false sense of security as a result of such occupant's erroneous belief that the sash is locked shut.
The present invention is directed toward solving the above prior art problems.